With the help of theoretical analysis，numerical calculation and in-situ observations，the structure around the tailentry in soft rocks and its deformation and failure regularity in pillarless fully-mechanized sublevel caving are mainly introduced. The in-seam distressing entry layout is combined with concussion blasting technique，so that the tailentry in soft rocks can be effectively maintained. Meanwhile，the general distressing principle and practical distressing program are discussed. The theory and practice prove that this is a scientific strategy and an effective deci-sion-making to bring the tailentry in soft rocks under control.